com.bigdata.resources
Class JoinIndexPartitionTask

java.lang.Object
  com.bigdata.journal.AbstractTask<T>
      com.bigdata.resources.AbstractResourceManagerTask<T>
          com.bigdata.resources.AbstractPrepareTask<JoinResult>
              com.bigdata.resources.JoinIndexPartitionTask

All Implemented Interfaces:

ITask<JoinResult>, Callable<JoinResult>

public class JoinIndexPartitionTask
extends AbstractPrepareTask<JoinResult>

Task joins one or more index partitions and should be invoked when their is strong evidence that the index partitions have shrunk enough to warrant their being combined into a single index partition. The index partitions MUST be partitions of the same scale-out index, MUST be siblings (their left and right separators must cover a continuous interval), and MUST reside on the same DataService.

The task reads from the lastCommitTime of the old journal and builds a single BTree from the merged read of the source index partitions as of that timestamp and returns a JoinResult. The task automatically submits, and awaits the completion of, an JoinIndexPartitionTask.AtomicUpdateJoinIndexPartition, which performs the atomic update of the view definitions on the live journal and the MetadataIndex.

Version:

$Id: JoinIndexPartitionTask.java 3343 2010-07-29 14:55:40Z thompsonbry $

Author:

Bryan Thompson

Nested Class Summary

protected static class

JoinIndexPartitionTask.AtomicUpdateJoinIndexPartition Task performs an atomic update of the index partition view definitions on the live journal and the MetadataIndex, thereby putting into effect the changes made by a JoinIndexPartitionTask.

Nested classes/interfaces inherited from class com.bigdata.journal.AbstractTask

AbstractTask.DelegateTask<T>, AbstractTask.InnerReadWriteTxServiceCallable, AbstractTask.InnerWriteServiceCallable<T>, AbstractTask.ResubmitException

Field Summary

protected com.bigdata.resources.ViewMetadata[]

vmd

Fields inherited from class com.bigdata.resources.AbstractResourceManagerTask

DEBUG, INFO, log, resourceManager

Fields inherited from class com.bigdata.journal.AbstractTask

checkpointNanoTime, concurrencyManager, isReadWriteTx, nanoTime_assignedWorker, nanoTime_beginWork, nanoTime_finishedWork, nanoTime_submitTask, readOnly, taskCounters, timestamp, transactionManager, tx

Constructor Summary

protected

JoinIndexPartitionTask(ResourceManager resourceManager, long lastCommitTime, String[] resources, com.bigdata.resources.ViewMetadata[] vmd)

Method Summary

protected void	clearRefs() Method is responsible for clearing the SoftReferences held by ViewMetadata for the source view(s) on the old journal.
protected JoinResult	doTask() FIXME Improve error handling for this task.

Methods inherited from class com.bigdata.resources.AbstractResourceManagerTask

toString

Methods inherited from class com.bigdata.journal.AbstractTask

assertResource, assertRunning, assertUnisolated, call, clearLoggingContext, dropIndex, getCommitTime, getIndex, getJournal, getOnlyResource, getResource, getResourceManager, getTaskCounters, getTaskName, getTimestamp, isResource, registerIndex, setupLoggingContext, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

vmd

protected final com.bigdata.resources.ViewMetadata[] vmd

Constructor Detail

JoinIndexPartitionTask

protected JoinIndexPartitionTask(ResourceManager resourceManager,
                                 long lastCommitTime,
                                 String[] resources,
                                 com.bigdata.resources.ViewMetadata[] vmd)

Parameters:

resourceManager -

lastCommitTime -

resource - The names of the index partitions to be joined. These names MUST be given in natural ordering of the left separator keys for those index partitions.

Method Detail

clearRefs

protected void clearRefs()

Description copied from class: AbstractPrepareTask

Method is responsible for clearing the SoftReferences held by ViewMetadata for the source view(s) on the old journal.

Note: This method MUST be invoked in order to permit those references to be cleared more eagerly than the end of the entire asynchronous overflow operation (which is when the task references would themselves go out of scope and become available for GC).

Specified by:

clearRefs in class AbstractPrepareTask<JoinResult>

doTask

protected JoinResult doTask()
                     throws Exception

FIXME Improve error handling for this task. See the build and split tasks for examples.

Specified by:

doTask in class AbstractTask<JoinResult>

Returns:

The object that will be returned by AbstractTask.call() iff the operation succeeds.

Throws:

Exception - The exception that will be thrown by AbstractTask.call() iff the operation fails.

InterruptedException - This exception SHOULD be thrown if Thread.interrupted() becomes true during execution.